High fidelity, real-time close combat simulation utilizes simulation of an aural environment in order to provide a student with audible cues that alert the student to the student's situation with respect to audible threats and other sound generating entities. For this reason, Three Dimensional (3D) sound simulation has become a part of high fidelity aural modeling, informing the student of his relative position to sound sources, reflective surfaces and room interiors. Even if all of the simulated sound components are generated with the highest fidelity, without modeling the 3D sound field, the acoustical environment will sound artificial and lack critical positional cues. An increasingly popular technique for simulating the aural effects created by 3D positioning of sound source, listener and reflective surfaces is convolution reverberation. Convolution reverberation has become popular over the last five years because of its high fidelity and the resulting ease of creating acoustic databases. These databases contain a set of recordings called impulse signatures that represent the aural characteristics or ambience of locations in space outside or within a room.
All physical systems respond to an impulse by resonating at their natural frequencies. The character of these resonances defines a unique aural signature for that space and the configuration of players within that space. A recording of that signature can be made. The aural signature of that space and the players can later be recreated and applied to a target audio stream that has no acoustical character of its own, by convolving the recorded impulse signature with the new target audio stream. The convolution is usually carried out by performing Fast Fourier Transforms (FFT) on the signal and impulse, multiplying their spectra, and performing the Inverse FFT (IFFT). Convolution reverberation creates the highest fidelity reverberation effect obtainable at present.